Question

CELL THEORY : 1. Matthias Schleiden, a German botanist observed that all plants are composed of different kinds of cells which form the tissues of the plant. 2. Theodore Schwann (1839), a British Zoologist, studied different types of animal cells and reported that cells had a thin outer layer (‘plasma membrane’). 3. Theodore Schwann also concluded that the presence of cell wall is a unique character of the plant cells. 4. Schwann proposed the hypothesis that the bodies of animals and plants are composed of cells and products of cells. Regarding 1,2,3 and 4:

Answer 1

the cell theory was defined for the in 1855, when another German biologist, R. virchow presented the idea that all cells arise from pre-existing cells (is actual aphorism was 'omnis cellula and Cellula').
Thus, the cell theory comprises of the following postulates:

Answer 2

Answer:

All living organisms are composed of one or more cells. The cell is the basic unit of structure and organization in organisms. Cells arise from pre-existing cells.

Matthias Jakob Schleiden was a German botanist and co-founder of cell theory, along with Theodor Schwann and Rudolf Virchow.